1. Field of the Invention
The present invention relates to temperature-controlled spaces, such as environmental chambers and, in particular, to a control system for controlling the temperature of such a space.
2. Description of the Prior Art
The aforementioned co-pending application Ser. No. 792,705 provides a modulated temperature control system which simultaneously controls the heating and refrigeration units in opposite directions substantially continuously between minimum and maximum heating and cooling conditions. However, that system utilizes an electronic suction throttling valve which requires an expensive modulation circuit to modify the control signal so that it is suitable for application to the throttling valve.